February 2, 2018
Contact: Vidushi Kumar at v.kumar@aicr.org

Coffee Doesn’t Need to Carry a Cancer warning, Scientists say it Protects from Cancer

A pending lawsuit in California is suing for coffee to be labeled with a cancer warning. If there is a favorable ruling, coffee houses in California would have to warn their customers about potential cancer risk and coffee companies may have to label their product.

The lawsuit focuses on the chemical acrylamide, found in roasted coffee beans, that has been linked to cancer in rats. However, strong evidence from the American Institute for Cancer Research (AICR) actually shows that drinking coffee reduces risk for endometrial and liver cancer. Coffee contains a variety of compounds that can block carcinogens, reduce cancer cell growth and promote cancer cell death.

According to the World Health Organization (WHO), acrylamide is found in nearly all food items including bread, corn, breakfast cereals, poultry and fish. The highest average levels of acrylamide were found in crisps and chips, ranging from not detectable to 3.5 mg/kg of the product. Although acrylamide increases risk for lab animals, no links have been established between acrylamide in food and cancer risk for humans as research is inconclusive.

To the contrary, scientists contend that coffee contains a variety of compounds that can block carcinogens, reduce cancer cell growth and promote cancer cell death.

Dr. Walter Willett, Professor of Epidemiology and Nutrition at Harvard T. H. Chan, School of Public Health says, “It will be really unfortunate if this happened because most of the human studies published so far have failed to find links between acrylamide and different types of cancer. We have looked at coffee, acrylamide intake, and acrylamide blood levels, and there is no hint of increased cancer risk, and in fact, we have only found health benefits of coffee per se.”

Coffee's possible link to cancer is a well-studied one, with over 1,000 studies on the topic. Relatively large and well-controlled population studies now provide good evidence that even up to six cups of coffee per day does not increase the risk of most cancers. Coffee contains vitamin B2 (riboflavin) and a variety of phytochemicals, many of which have antioxidant properties.

Dr. Ed Giovannucci, is at Harvard T. H. Chan School of Public Health and studies the links between lifestyle factors and cancer risk. He says, “We have studied coffee for decades now and have enough evidence from large, well-designed studies to say that coffee is protective for some cancers. We can confidently say that coffee is not harmful and certainly doesn’t have to be labeled the way we label tobacco, which is actually proven to be harmful and causes many cancers.”

There are several hypotheses on how coffee may decrease cancer risk. Coffee is a major source of antioxidants. Limited small intervention studies suggest that coffee may improve markers of antioxidant status and reduce markers of inflammation in the short-term. Animal studies and human studies both suggest that regular and decaffeinated coffee may decrease insulin resistance, a condition that leads to high insulin levels in the body. Reducing insulin resistance could help reduce the risk of cancers whose growth is promoted by excess insulin.

Coffee is also a source of compounds that cell culture and animal studies suggest may shift estrogen metabolism, growth factors and regulators of cell growth to reduce cancer cell growth. Also, caffeic acid in coffee seems to serve as an antioxidant that increases the pace of self-destruction of cancer cells.

Coffee contains:

  • Chlorogenic acid, an antioxidant compound that is the major phenol in coffee
  • Quinic acid, a phytochemical that contributes to the acidic taste of coffee
  • Cafestol and kahweol, compounds that are extracted from the beans' oil during brewing. Unfiltered coffee, such as French press or boiled coffee, contains these compounds
  • Caffeine, a naturally occurring stimulant that affects the central nervous system
  • N-methylpyridinium (NMB), created by roasting, may make the antioxidants more potent

 

Additional Resources on Coffee: http://www.aicr.org/foods-that-fight-cancer/coffee.html